Rotary well drill



Feb. 7, 1928. 1,658,125

} E. s. HUTTON ROTARY WELL DRILL Filed Oct. 6, 1924 FIE 1 INVENTOR.

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Patented Feb. 7, 1928.

UNITED STATES EDWARD S, HUTTON, 0F MUSKOGEE, OKLAHOMA.

ROTARY WELL DRILL.

Application filed October 6, 1924. Serial No. 741,996.

This invention is for the purpose of rapid rotary drilling of holes ofrelatively large diameter in the ground, chiefly for oil well purposes.

This invention is in a rotary drill having a fish tail or other bit forpiloting the drilling apparatus; that is, for drilling a smallhole-,rand means immediately following said fish' tail bit for enlargingthe bore of the hole.

Another feature of the invention consists in theapparatus for drillingthe enlarged hole, being such that it can be introduced into the wellpipe and after it passes the lower end of the well pipe, it will expandfor drilling the enlarged hole and thus serve as an under reamer fordrilling a hole of larger diameter than the well pipe.

I have found that it is much more economical and rapid to drill a centerhole and ream it, and particularly to do the same simultaneously, thanto drill the-enlarged hole by one bit. In other words, it is much easierand more rapid to enlarge a small hole than to entirely dig the largehole in one operation. I

The full nature of the invention will be understood from the followingdescription and claims and the accompanying drawings:

In the drawings, Figure 1 is a central vertical section through saidwell drilling apparatus thetop and bottom portions being broken away,the drill being within the well pipe. Fig. 2 is the same showing thedrill- 1ng apparatus immediately below the lower end of the well pipe indrilling condition, the fish tail bit being, however, removed. Fig. 3 isa horizontal section on the line 3-3 of Fig. 1. Fig]. 4 shows a detailedview of drilling disks. E

There is shown hereinan'oil Well pipe 10 and within it there is atubular drilling stem 11 of usual character which is rotated during thedrilling operation. The lower end of it is internally threaded and intothat there is secured the reaming or hole enlarging drill. This consistsof a head 12 which has a threaded upper projection for screwing into thestem and the lower portion of said head is transversely enlarged andmade tubular and internally threaded to receive the threaded upper endof the body 13 of the tool. Inthe portion of the body of the toollocated below the head- 12 there is a diametric opening 14 entirelythrough the same, as seen in Figs. 1 and 2, for receiving the shanks 15of the cutting disks 16. The walls of the opening 14 are of peculiarshape. The central portion of the upper wall is substantially straightdiametrically, but each end 17 slopes upwardly. The bottom wall 18 isdoubly curved, each curve extending half way through the body of thetool and its inner ends curved upwardly, while the outer portion ofeach'of said end portions of the bottom.wa1l 18 is almost perpendicular.to the side wall of the tool. The sides of the opening 14 are shown inFig. 3. They are vertically straight, but they have vertical shoulders19 made by widening the inner portion of the opening 14, thus leavingcontracted outer portions, as shown in Fig. 3.

The shanks 15 of the drilling disks 16 have a peculiar shape. They restloosely in the ends of the opening 14 and the lower surface 115 of eachshank is curved substantially the-same as the curvature of the bottomwall of the opening 14. The sides of the shanks 15 are vertical, butthey have a widened portion 20 at their inner ends, forming on theopposite sides, shoulders, the side of said portions 20 being asindicated in Fig. 2, that is, a right angle triangle with the acute endcut away, somewhat in the nature of a trapezium, so that when the shanksare in their outer position, as shown in Fig. 2, they will be preventedfrom escape by said shoulders 20 engaging the shoulders 19 of the toolbody, and in that position the engaging surfaces of said two shouldersare vertical. When the shanks are in their inner position,

as shown in Figs. 1 and 3, the shoulders of thelportion 20 are obliqueto the axis of the too The cutting disks 16 are mounted in. the form:herein shown, as illustrated in Fig. 3. The disk has an annular slopingor conical cutting surface and it has a central threaded opening,whereby it is screwed on the threaded end of a sleeve 25 that fits in ahole 26 in the shank 15. Said sleeve is'held in place by a headed bolt27 that has a threaded inner end which screws into or through a centralthreaded opening in the inner wall of the shank. These cutting disks maybe varied in shape, that shown in Figs. 1 and 3and the right-hand end ofFig. 4, having smooth beveled cutting surfaces, but, if desired, thecuttin surface may be annularly corrugated, as s own in the twoleft-hand forms in Fig. 4. The cutting surface of these disks varies tosuit the material through which the well is being drilled. The

outer surface of the cutting disk is preferably convex. That enables thetool to be passed readily through the well tube 10 and strengthens thedisk.

The disks are position 'a-ftert ey pass beyond the lower end of the wellpipe by a spring 30 located in a vertical chamber 31 in the-center ofthe body 13 of the tool, and extending from the upper end thereof downthrough the transverse opening 14. There is a cap shaped plunger 32 atthe lower end of the spring, having a lower convex beveled surface whichengages the top surfaces of the shanks 15 of the cutting disks neartheir inner ends, as seen in Figs. 1 and 2.

The lower end of the body 13 of said tool has a central threaded socketfor receiving the upper threaded end of a fish tail bit 35 or a bit ofany desired form for drilling the narrow or pilot hole.

In operation the drill is inserted in the well'pipe, as shown in Fig. 1,with the cutter 16 in contracted position. After the dl'illl passesbelow the tube, thespring 80 forces them out into cutting position, asshown in Fig. 2, and in that position they are obliquely disposed withreference to the axis of the tool, sothat as the tool revolves, saiddisks will drill the earth below and to a greater diameter than the walltube. By beveling the cutting surface, as shown, the disks willautomatically be pulled and held in their outer positions by the earthmaterial being cut, and they will be limited in their outer movements orpositions by the shoulders of the tool shanks engaging the shoulers inthe opening of the tool body in which they are mounted. Hence, thefunction of the spring 30 is to force the disks out into cuttingposition rather than to hold them in cutting position. During theoperation of the tool, the fish tail pilots the same and drills a smallhole while the reaming drill above associated therewith follows andenlar es said hole by reaming it.

n advantage is that one may start with this tooland go as far aspossible without setting pipe and then he can put in the string of pipeand after doing so, lift the pipe a few feet off the bottom and hold itwhile introducing his tool through the pipe pushedoutward into cuttingto a point below the same and then lower the pipe as fast as the hole ismade, thus saving extra strings of pipe. This is due to the devicedrilling a hole of larger diameter than'the pipe and yet beingintroducible through the pipe. i l

The invention claimed is: p

1. Well drilling means for the introduction of a well pipe having arotary body portion with openings. in opposite sides thereof, the lowerwalls of which are oppositely curved outwardly, a pair of oppositelylocated cutters with shanks projecting into said openings having thelower surfaces curved to conform with the bottom walls of said opening,and whereby said shanks are substantially horizontal while in-contractedposition, and a-spiral spring located centrally of said body portion andacting downwardly against the inner ends of the shanks of said cuttersfor expanding them.

2. A well drilling means for the insertion of a well pipe having arotary body portion with radial openings on opposite sides thereof,oppositely located cutters with their shanks in said openings "arrangedso that they will, in contracted position, be substan tially radial andin expanded position the cutters will have their lower portion tiltedoutward, and a spring which forces the in ner ends of said cuttersdownward and tilting their outer ends upward and outward to theirexpanded position, the shanks of the cutters having widened shoulderends and contracted outer portions of said opening forming shoulders toengage and stop the shoulders of the shanks of the cutters, whereby thetools will be held in place against outward movement when expanded,substantially as set forth.

3. Well drilling means for insertion of a well pipe having a rotary bodyportion, the said body portion having radial openings, a lower end ofeach opening having'an arcuate wall, a cutter shank in each opening,arcuate bearing surfaces on said shanks engaging and being guided bysaid arcuate walls, a spring which forces said shanks to move in onedirection, and cutting elements at the outer ends of said shanks.

In witness whereof, I have hereunto affixed my signature.

EDWARD S. HUTTON.

